In the construction of buildings and mechanical systems, a newly installed or repaired fluid transfer system or system component, as for example a building plumbing or sewage system, must frequently be isolated from a larger system until the fluid-tight integrity of the new section is tested, generally by subjecting the system to an increased fluid pressure to locate any leaks. In building construction, system tests of this kind are often required as a condition of certification of compliance with building code requirements. The inherent difficulty of making pressure tests of this type is often aggravated by the fact that some portion of the new installation is embedded in a wall or is buried, obstructed by other components, or otherwise difficult to access at the time the test is conducted. Thus a vexing question has been posed by the need to seal selected portions of such systems in order to accommodate testing without permanent obstruction or other damage to the system.
Several solutions to the problems of completing such tests have been offered, including those disclosed in my own previous U.S. Pat. No. 4,848,155, 4,936,350, 5,033,510, and 5,163,480, and in my previous patent applications Ser. No. 60/092,313, filed Jul. 9,1998 and entitled Water Closet Fitting with Test Baffle; Ser. No. 60/092,322, filed Jul. 9, 1998 and entitled Water Closet Fitting Installation Assembly; Ser. No. 60/093,682, filed Jul. 22, 1998 and entitled Test System for Fluid Tight Integrity of Installed Pipeline; and Ser. No. 60/102,372, filed Sep. 29, 1998 and entitled Test Assembly for Fluid Tight Integrity of Pipeline Joint. The disclosures of each of these patents and patent applications is incorporated herein by this reference as if set forth in full.
Each of the incorporated references discloses systems for the leak or pressure testing of pipelines and other fluid conduits, the systems comprising removable test baffles adapted to seal off portions of the fluid conduits and later to be removed without permanently obstructing or damaging the fluid systems. When making tests by means of such baffles, it is frequently advantageous to be able to dislodge, unseat, or remove the test baffle without permitting fluid within the system to leak while the system remains sealed. That is, it is frequently advantageous or important to accomplish the release of pressure within that portion of the conduit which has been tested, or the removal of the test baffle, or both, while the system is sealed without allowing the discharge of significant or uncontrolled amounts of fluid. It is also advantageous to be able to remove the tool or device by which the baffle is unseated or dislodged without having to open the system or permit leakage or drainage therefrom. Several means for accomplishing the unseating of test baffles have been suggested--particularly in the incorporated references--but they do not in general provide a means for doing so without leakage or other release of fluids, or for the removal of unseating tools without leakage. For example, several of the systems disclosed are best suited to use with an open free end of a conduit, as for example an open end of an uncompleted pipeline, or require opening of the system to remove the dislodging tool. Others of the systems provide for access from Y-joints or cleaning or maintenance points, but only with the end plates or covers removed.
Sullivan, U.S. Pat. No. 4,429,568, discloses a closure plug assembly for pressure testing liquid drain and vent plumbing pipe systems. Tagliarnio, U.S. Pat. No. 4,542,642, discloses a test tee having a plug which is a removable blocking disk. Ver Nooy, U.S. Pat. No. 3,154,106, discloses a pipeline plugger. Svirsky, U.S. Pat. Nos. 2,279,257; 2,299,116, and 2,299,434 disclose various plugs and closure means for conduits. Fischer, Swiss patent No. 313,441, discloses a test plug for a Y-shaped, dimpled pipe. Roberson, U.S. Pat. Nos. 4,203,473 and 4,658,861, discloses plug assemblies. Each of the above references, however, requires removal of a plug or other test fixture to facilitate removal of the dislodging tool. Many of the tools, moreover, do not permit dislodging or unseating of the test plugs, or the release of test pressures within the system, without venting the system and opening possibilities for leakage or other drainage.
Another difficulty with making tests of the type described is that a single tester is often required, over the course of hours, days, weeks, or even longer periods, to test portions of systems which comprise conduits of differing inside diameters. For example, most fluid conduit systems such as building plumbing and pneumatic systems use conduits of differing, but standard, diameters. In building construction, for example, pipe diameters varying between 1/2" and 6" are common, and are frequently used within the same building in different portions of the same plumbing systems. The advantage of having a single test plug or system which would permit testing of two or more standard conduit sizes, without changes or modifications to the plug, is clear: the tester is able to perform the same function while carrying fewer plugs, and therefore has less weight and fewer components to transport. Convenience, safety, and economy are all improved.
None of the prior art references discussed herein discloses a test plug adapted for sealing the end of 2 or more pipes of differing diameter, so that the burden of carrying multiple test plugs is imposed upon the users of such systems. Given the bulk and weight of such plugs, and the desirability of making test equipment easily portable, it may be seen that any requirement for carrying multiple test plugs is to be avoided.
Thus there is a need for a test plug or cap which will permit dislodging of a test baffle for a system for the non-destructive and non permanently-obstructing testing of the fluid tight integrity of an installed fluid transfer line such as a drain pipe or vent and wastewater system of a building, the test baffle being disposed within a sealed or substantially sealed fluid conduit, without removal of the plug and without leakage or other drainage from the fluid system after the test has been completed. There is a further need for such a test cap which will permit removal of the dislodging tool without removal of the cap and without such leakage or drainage. There is still further need for such a test plug or cap which is suitable for use with a plurality of standard-sized fluid conduits. It is further desirable that such a test plug or cap not require the employment of a T- or Y-fitting for access to or removal of the test baffle, or separate access covers, and that it not require the replacement of parts or seals following completion of the test or the use of pneumatic or otherwise inflatable apparatus in performing the test.